Boiler setting



Patented May 6, 1924.

UNITED 'STATES Parleur eFH-CE..

GEORGE NAISMITH, or PITTSBURGH, PENNSYLVANIA l i -IBOILER SETTING.

` Application nled March 16, 1922. .Serial No. 544,165.

tain new and useful Improvements in Boiler Settings, of which'thefollowing is aspecication.` Y

My invention relates to animprovement in ,boiler setting, and moreparticularlyto the construction ofthe enclosing walls of the furnace,with a view to providing forv preheatingof the air for the fuel. `It hasinV .view tov preheat the incoming air, prior to its admission to thefurnace chamber for Acombustion with the fuel, as pulverized coal,

byy passing the air alternately through checkerwork` heated bypreviously burned products of combustiomwith means for effectingalternating reverse'circulation of the air, so as to. utilize the wasteheat to the best advantage. c l

The yinvention Yis illustratedl in one preferred form, showing itsyapplication to a standard double installation of water tube boiler ofthevertical type, but is not restricted to any special installation orconstruction of the boiler elements themselves."

:In thedrawings,

V Fig.4 1 is a vertical sectional view through a boiler setting showingthe circulation of the fuel and waste gases across, through the furnacechamber and heating elementsof a water tube boiler ;4 I

4Fig. 2 is a horizontal section on the `line II-II of Fig. l;

Fig-3 is artransverse vertical section on the lineIII--III of Fig. 2.

'The boiler construction is of typical form utilizing upper steam supplydrums 2 connected by banks of tubes 3, with'lower mud drums 4 with anupper steam collecting drum 5 and the various usual connections andother parts not necessarily hereindescribed. It will be understood,also, that the invention is non necessarily dependent on the use ofbailles, which may be utilized' or not, as desired, to control ordeflect the gases in circulation between the tubes 3, it beingunderstood that the heated air is'to be introduced through openings inone inner wall and, after combustion with the fuel and circulationacross through the tubes, to pass outwardly romthe chamber, throughcorresponding vopenings in the opposite inner wall, in periodicalalternating directions.

The combustion chamber a containingthe vboiler installation is enclosedwithin a surrounding wall lstructure. comprising front and back walls13`- 14, and companion inner Walls 16-17 respectively, with interveninglouter circulation chambers containing'r'lthe checkered refractoryymateriall, ofjwelll known construction, andA inner downwardly extendingair Adelivery chambers c. The checker chambers, air chambers, andthecombustion chamber are closed atthe top, f

lwith La covering roof 6, and they communicate by bottom Atransverse,conduits 18 through conduitsor llues 19 between upper andlower floor-orbottom walls 20e-21 respectively.. Such bottom walls form, in :effect,extensions ofinner walls 16-17-and Vouter walls 13--14 to provide forthe desired circulation outwardly from` andy inwardly towards `thereversing valve A, located in the lower lmiddle portion of thestructure. Al y i Said valve, which is of the usual Siemensconstruct-ion, is located within asegregated open ended chamber b withinand between the inner boiler-supporting walls `22-,22, above the floorwall ,20 andbelowan enclosing upper partition 24. Chamber b communicateswith the outside stack by an outlet conduit 25 for thewaste4 gases, andair ,is supplied to the valveA from -the atmosphere by-the end openings26 leading to the middle upper intake opening 27 of the valve,

as is generally understood. y i

The reversible gate 28 is pivot'ed midway of the Valve casing and bymeans of suitable` operating connections is adapted to be thrown toalternating positionsito direct incoming air from opening 27 through theend circulating open channel 29 ofthe valve to the lower communicatingconduits or channels 19 and 18, the latter leading upwardly to thechecker chamber 15 at the receiving side of: the furnace chamber.FueL-.inj the form of pulverized coal, isadmitted through the series ofopenings 7 in the roof of the furnace, or in any other suitable manner,whereby to pass downwardly into the combustion chamber at.v The incominghot air first passes from the top of the checker chambers containing therefractorypmaterial 15 downwardly through chamber @and then into thecombustion chamber va through llO a, the burnt gases pass inwardlythrough ports 8, upwardly by chamber c to the corresponding checkerchamber 15, downwardly therethrough to channel or conduits l819, y

then upwardly through the other or closed circulating cavity 29 of thevalve, and finally down through conduit 25 to the stack. It will beunderstood, of course, that the supply of powdered fuel through openings7 alternates with the alternating valve control. Also, that the ports 8provide for the circulation of the gases as just described, inalternating directions, as the valve is periodically reversed. 1

The operation of the invention will be readily understood from theforegoing description. Air is circulated in one direction or Vthe otherfor a period of time, say twenty minutes, sufficient to absorb the heatfrom the previously heated checlrerwork refractory material at one sideof the chamber a, before issuing thereinto. At the same time, theoutgoing waste gases of combustion pass by ports 8 and channel c intothe checkerwork chamber at the opposite side, thereby heating thecheckers for the next operation, on reversal of the valve.

By kproviding the inner walls 16-17 with the numerous ports 8, bothvertically and transversely throughout substantially the entire heightand width, `the air is broken up and distributed by the checkerwork andsuch ports, so that it enters the combustion lchamber in substantiallyequal volume and rate of iiow at all portions of the chamber. Theresulting e'ect is that, assuming the proper proportion and quality offuel is being supplied, a very even and consistently unvarying heat ismaintained across the entire area of the furnace chamber. with theresulting advantage of regular and economical heat transmission to thewater in circulation through the headers 'or drums and their connectingtubes.

The advantages of the invention will be lreadily understood andappreciated by all those familiar with boiler practice, and it may beapplied to different standard types or designs of boilers, by merelyadapting the arrangement of the checker chambers and their inner wallsand ports as to location, size, number. etc., to suit any particularinstallation. All such changes may be made by the designing engineer orbuilder, and are to be understood as within the scope of the followingclaims.

What I claim is:

l. In boiler construction.y the combination with a centrally arrangedwater tube boiler, of a surrounding roof and wall structure providing anenclosing combustion and circulation chamber, each opposite end portionof the wall structure providing a main circulation chamber open at thebottom and top and containing refractory checkerwork and having an innerkwall provided with series of vertically and horizontally arrangedcircula-V tion ports communicating inwardly with the combustion chamber,an intervening partition spaced therefrom terminating below the roof,forming the inner wall of the refractory chamber and providingcirculation therefrom and thereto with the inner wall ports, and meansproviding circulation to and from the open bottom of each outermostrefractory chamber.

2. In boiler construction, the combination with a centrally arrangedwater tubeboiler, of a surrounding roof and wall structure providing anenclosing combustion and circulation chamber, each opposite end portionof the wall structure providing a main circulation chamber open at thebottom and to and containing refractoryT checkerwork an having an innerwall provided with series of vertically and horizontally arrangedcirculation ports communicating inwardly with the combustion chamber, anintervening partition spaced therefrom terminating belowthe roof,forming the inner wall of the refractory chamber and providingcirculation therefrom and thereto with `the inner wall ports, a middlesupporting wall structure below the boiler providing an air supplychamber, and a reversible valve and casing therein providingcommunication between the bottom of each refractory chamber and withthe-air supply and exhaust respectively.

3. In boiler constructiomthe combination with a centrally arranged watertube boiler, of a surrounding roof and wall structure providing anenclosing combustion and circulation chamber, each opposite end portionof the wall structure providing a main cir-r culation chamber open atthe bottom and top and containing refractory checkerworl; and having aninner wall provided with series of vertically and horizontally arrangedcirculation ports communicating inwardly with the combustion chamber, anintervening-partition spaced therefrom terminating below the roof,forming the inner wall ofthe refractory chamber andproviding'circu'lation therefrom and thereto with the inner wall ports,a middle supporting wall structure below the boiler providing an airsupply chamber, a reversible valve therein having a casing opening tothe atmosphere and to an exhaust conduit respectively, and independentconduits connecting said casingwith the base of each checlrerworkchamber respectively whereby to effecty alternating circulationtherethrough.

4. In boiler construction, the combination with a watertube boiler, of asurroundingv tory chamber spaced from the innermost support for theboiler, and a reversible valve Wall providing a circulation spacecommunitherein communicating with the base of each 10 eating with theupper end of the refractory refractory chamber, With the atmosphere,chamber, series of vertically and laterally and with an exhaust conduit.

arranged ports through the innermost Wall In testimonyy whereof Ihereunto alix my establishing circulation between said space signature.

and the combustion chamber at each end, a

middle covered valve chamber serving as a GEORGE NAISMITH.

